采样率多少

绝大多数 Apple Music 曲目的采样速率是 44.1KHz。你也可以在电脑上通过 iTunes 查看曲目的采样速率等信息。

Apple Music 的格式主要继承自 iTunes Plus AAC 格式。而这一格式选用这个采样速率主要是继承自常见 CD 的采样速率。

An iTunes Plus AAC file uses a sample rate of 44.1kHz and is encoded with a target bit rate of 256 kilobits/second.

The standard for CDs is 16-bit 44.1kHz resolution, meaning that the analog signal is sampled 44,100 times per second and each sample is given a value between -32,768 and 32,767. This resolution is often referred to as 44/16.

摘自 https://images.apple.com/itunes/mastered-for-itunes/docs/mastered_for_itunes.pdf

上面的文档还详细叙述了关于更高采样速率的思考，以及选用 44.1KHz 的更具体原因。